The Weston
Ranger 9 from 1966 was a departure from the Weston formula. It used a
Cds cell instead of selenium for greater sensitivity and had a very narrow
measurement angle. This meter has a viewfinder, similar to those found
on cameras. You look through the viewfinder to determine the area being
read.It was a favourite of Ansel Adams who found it perfect for his Zone
system of exposure/developing/printing - a system infinitely boring but
it worked for him. There was also a special zone system dial that could
be purchased. It's completely dependent on battery voltage, and won't
read correctly at anything other than 2.70 volts (two 1.35 cells, or the
single stacked version) .

The batteries
are no longer made but Wein can supply equivalents.

Here are some of the features listed in the booklet: Interchangeable
calculators